this isnt how slayer used to work, you got slayer points for killing things not from task streaks. However, yes i can see that being a issue now that its like this... maybe if they select random boss tasks they get a random amount and dont get to choose kc amount.
-- this got removed w/ slayer rework which was when the streaks were added and pts at end of tasks rather than killing stuff
No, streaks were very much a thing in the old slayer design.
Here is some details of how it used to work, you could easily get 200+ points for a 3kc boss task that takes a minute or two.
This is how slayer worked from 2017 to 2020:
Base points:
Normal task:
CB 1-50: 1 point
CB 51-99: 2 points
CB 100-199: 3 points
CB 200+: 4 points
Special tasks:
Wilderness bosses: 5 points
Extreme tasks: 5 points
TzTok-Jad: 8 points
TzKal-Zuk: 12 points
Wilderness tasks:
Double any of the above points (eg. Wildy bosses give 10 instead of 5)
After you have determined the base points, the extra points for your streak are calculated as follows:
extraPoints = basePoints * streak
If your streak is >30, the calculation will max it out at 30.
For example, if you defeat TzTok-Jad at a streak of 30 tasks, you will receive (8 * 30) = 240 bonus Slayer points.